Wireless telegraphy



Aug. 12 1924. 1,504,426

w. M. BRUCE, JR

WIRELESS TELEGRAPHY Filed July 7, 1919 V 2 SheotO-Shtt 1 PRINGFIEL D OHIO wi hmoa Aug. 12 1924. 1,504,426

W. M. BRUCE. JR

WIRELESS TELEGRAPH! Filed July 7, 1919 2 shcotmcet 2 Patented Aug. 12, 1924.

warren STATES WILLIAM 211'. BRUCE, J'B., OF SPBINQFIE-D, OHIO.

\ I WIRELESS TELEGRAPH.

Application filed m 7, 1919. Serial No. 809,186.

To all whom it may concern:

Be it known that I, WILLIAM M. Barron, Jr., a citizen of the United States, residin at Springfield, in the-county of Clark an State of Ohio, have invented certain new and useful Improvements in Wireless Telegraphy, of which the following is a 'speci cation. 7

M invention relates to improvements in wire ess telegraphy.

The object of the invention is to rovide methods and apparatus for translatingthe train of wireless waves so that the same can be readfrom an ordinary sounder or recorder and a record made thereof.

While many attempts have been made to translate and record wireless impulses, no method as yet has been found to be commercially successful and it is the common,

if not universal, practice to receive wireless messages on telephone receivers, the receiving operator reading the messages from the sound produced by the vibrations of the telephone receiving diaphragm but of which no permanent record is made, so that if the operator fails to get any part of the message the same is lost and requires 2 repetition. This situation is aggravated in those cases where the static in uences are resent and if the static currents are of sufcient frequency and intensity the messages are, so far as legibility to the ear is concerned, obliterated.

I have been able to translate wireless messages by the aid of my improved method so that the can be read on an ordinary sounder or a siphon recorder and a permanent record made thereof and this under ordinary traflic conditions and at speeds which render it entirely commercial a by very simple method and ap aratus.

In carrying out t ie invention I employ a bulb or vacuum tube detector which is connected to the receiving aerials by the usual circuit and in the local circuit of this detector I place a receiver of the movable coil type in series with a condenser and battery, with a shunt around th receiver 7 and the condenser and as each train of wireless waves will reduce the potential of the id element of the detector the condenser will be charged through the receiver coil and move it in one direction. and when the wireless waves cease, allowing the grid potential to increase the condenser will discharge through the shunt and the receiver coil and thus move it in the opposite direction. If the receiver is a relay of a proper type its movements may be transferred through a local circuit to an ordinary sounder which will translate its movements directl as they are effected by the charging and t e discharging of the condenser through the receiver.

lVhere the impulses are affected by static conditions I substitute for the sounder orsimilar translating device a siphon recorder which will record not only the signals formed by the trains of wireless signal waves but also record the static effect but in such a manner that the static currents will cause the writer to record by rapid up and down movements while the signals caused by the train of wireless waves will be recorded in a longitudinal direction upon the tape or strip upon which the siphon is operating, it being perfectly feasible and practicable as has been demonstrated by actual working conditions to make a record that is entirely legible even when static charges of rapid and giwintensity are impressed upon the circuit inasmuch as this method of receiving and recording the'messages is such that the static charges will cause the writer to move with great rapidity across the paper and within the signal itself without destroying the signal although both the static and the train of wireless impulses will be recorded.

I accom )llSll the above named object by the metho and means hereinafter described and brought out in the claims.

In the accompanying drawings Fig. 1 is a diagrammatic view of a simple a plication of my invention to a wireless circuit and to a receiver of the movable coil type which would be preferably in the nature of a relay from which other devices could be operated to properly translate or record thc'signals or which could be itself embodied as a direct writer such as a siphon recorder.

Fig. 2 is a more extended diagrammatic view showing the preferable arrangement of local circuits in connection with the receiver for translating the signals on a recorder or sounder in dots and (lashes cor responding to the ordinary Morse or Continental code.

Fig. 3 is a view showing a sample of the si nals.

Fig. 4 is a view substantiaily similar to Fig. 1 with a siphon recorder substituted for the relay.

Fig. 5 is a view similar to Fig. 2 with a si hon recorder in the local circuit substltuted for the relay e.

In the said drawings the numerals 1, 2 and 3 represent the filament grid and plate of a wireless detector of the bulb or vacuum tube type which would be connected to the usual receiving aerials by the ordinary wireless detector circuit. The battery I) is connected in the local circuit to the elements 1 and 3 by the wires a, e and f and this circuit includes a condenser c and movable coil receiver (1. Across the wires a and e is a shunt 3 having therein resistance r, thus shuntin the condenser and the suspended coil of the receiver (1.

When the train of wireless waves is impressed upon the detector, the potential of the grid will be reduced and increased current will flow from the battery thro'u h the receiver coil into the condenser whi will thus be charged and move the coil in one direction, and when the wireless impulses cease the potential of the grid will be increased, thus decreasing the battery flow, causing the condenser to discharge into the shunt and move the receiver in the opposite irection. If the train of wireless waves are of short duration the relay will be moved to its forward or marking position for a short interval and if they are of long duration it will be moved and held to its marking po sition for a longer period, this making the dots and dashes of the ordinary code signals. It remains, therefore, only to supply suitable circuits to the circuit translating devices which will either record the movements of this receivin device or operate further mechanism w ich will translate these received impulses into the proper signals, such as a sounder or a recorder.

I have shown in Fig. 2 the preferable method of translating the signals on a recorder b using a selenium resistance It and I provi e on the suspended coil of the receiver. a mirror (1* which operates in connection with a lamp L, lenses L, screen L and lens L so that as the coil is deflected the mirror is caused to project a ray of light on or off this selenium resistance. This selenium resistance preferably consists of two or more cells h and h and is connected to the batteries 6 and b and relay e by the wires a, a and 0 I also provide in connection with this relay a condenser c of high capacity. V The light nor mally is thrown onto the resistance It so as to partly illuminate both sides thereof. As it moves from side to side, it will increase the resistance of one cell and decrease the resistance of the other, which will cause currents of opposite polarity to flow from the batteries b and b, as the case may be, and

thus operate the relay e, in a direction corresponding to the polarity of the current.'

As currents of opposite polarity are supplied firstfrom one battery and then from the other, an alternating current will be sup plied which will pass through the condenser c to operate the relay e and by using a condenser of high capacity, dashes can e recorded due to the slow discharge of the condenser into the relay circuit. The relay e is also preferably of the suspended coil t pe and may be supplied with a tongue t an suitable, contacts 'to operate a local circuit in any desired and well known manner.

Where the static influences are present, I substitute for the relay e a direct writer 8. 1'. Figs. 4 and 5 of the siphon recorder t pe. These static influences will affect both tlie receiver a! and the writer operated thereby, but as these static discharges are very sharp and of rapid movement they will cause the direct writer to vibrate rapidly and violently up and down and'across the si als representing the dots and dashes su stantially in the manner shown in Fig.

3. While the siphon recorder will be moved up and down across the paper at the beginning and at the end of each signal, that part of thesignal only at the top of these movements is read and by laying a paper or straight edge along the tape so that onl the tops of the characters appear these wi l readil appear as dots and dashes.

Un er certain conditions of operation and if the static influences are present the direct writer or siphon recorder can be placed directly in circuit with the battery and the plate element of the detector as shown at s. r. in Fig. 4 and the selenium or other form of role can be dispensed with.

As shown in t e drawings, the shunt around the condenser which is in series with the recorder is provided with a plain resistance which permits the condenser to discharge through the shunt and also prevents the flow of battery through the recorder except when the condenser is being charged or discharged as a result of the train of high frequency waves impressed upon the vacuum tube. This maintains the movable coil of the recorder in a zero position at all times except when moved by the charge and discharge of the condenser as noted, thus maintaining the movable coil free from bias and capable of responding at high speeds to the trains of wireless waves impressed upon the vacuum tube.

Having thus described my invention, 1 claim:

1. In a system, for recording wireless signals consisting of trains of high frequency currents of long and short duration, a vacuum tube detector to change said high frequency trains of currents into uni-directional currents of the same duration and a recording device having a movable coil and a movable tape means for causing said coil to be 0 rated in one direction at the beginning o the flow of said uni-directional cur rents and to be retained in said moved position during the continuance of said current and to move to zero position at the end of said current flow, said coil being provided with a proper stylus which will mark the 'tape in the direction of its travel during the continuance of a train of wireless waves so that the signals may be read lon 'tudi nally of the moving intervals representing dots and ashes.

2. In a system for receivin wireless signals, of long and short impu see, a detector for roducing uni-directional currents from the high fre uency currents, and a recording device capa le of moving in opposite directions across a moving tape, means for causing said recording device to move across the tape in one direction at the be 'nning of a s1 al and to be retained in t is position uring the continuance of the signal and to be moved in the o posite direction at the end of the signal, movement of the recorder being such that it will mark the duration of the respective si als in a longitudinal direction and in su antially the same line longitudinally of the ta 3 In a system of receiving an recordwireless signals of long and short imu see in the presence of static or other isturbances, a detector for producing unidirectional currents from high fr uency waves, a recorder capable of moving in opposite directions across a moving tape, means for causing said recorder to move to one position across the tape at the begin ning of thesignal and to be held in this position during the continuance of the sigtape, the lon an short nal and to be moved to its normal position at the end of the signal and to be held in this position in the interval between the signa s, with means in said recorder for marking the tape in the respective positions in a longitudinal direction of the tape, while static or other disturbances will be recorded across the signals without obliterating the same.

4. In a receiving circuit for wireless communications, the combination, with a vacuum tube detector, of a movable coil receiver, a battery and a condenser in the plate circuit of said detector, a shunt around the receiver and condenser and resistance insaid shunt to cause the high fre uency currents to charge and discharge sai condenser throu h the movable coil of said receiver b cfianges in the potential of the detector e ement, a stylus controlled by said movable coil, a movable tape moving substantially at right angles to the movement of said stylus whereby trains of high frequency waves of long and short duration will cause said stylus to move across the tape from a normal or zero 'tion to a marking position and to be lizfl d in this position so long as the train of high frequency waves continues and to be moved back to its normal position when said high frequency waves cease whereby the duration of each group of high frequenc waves will be recorded ongitudinally on t e tape in a substantially straight line in one position while the intervals between the groups of waves will be recorded in a substantial parallel line in zero position.

In testimony whereof, I have hereunto set my hand this 27th da of June, 1919.

WILLIAM BRUCE, Jn.

Witness:

Case. I. Wmwn. 

